Spec Fidelity
How faithfully an implementation matches its specification, expressed as one reproducible number. Tests, linters, scanners, and review each measure code against an external standard. Spec Fidelity is the only one that measures it against your spec.
Why it is not testing, linting, QA, or review
Assert behavior you wrote
A test encodes what a developer expected. If the developer misread the spec, the test passes and the requirement still fails. Tests cannot catch a faithful-looking misread.
Enforce style, not meaning
Linters keep code consistent and safe from a class of bugs. They have no model of what the feature was supposed to do.
Samples behavior late
Manual and automated QA find issues after the build exists, against test plans that are themselves a lossy copy of the spec.
Judges craft, under time pressure
Reviewers check quality and taste on a diff. Few re-read the full requirement for every line, and AI diffs are large and plausible.
Match known risk patterns
Scanners look for vulnerability signatures. A correct-but-wrong feature has no signature to match.
Measures faithfulness to intent
Norma reads the requirement and the implementation and judges whether they agree. That is the gap every other tool leaves open.
Why existing tools miss this
| Tool | What it checks |
|---|---|
| Tests | Behavior |
| Linters | Style |
| Code review | Code quality |
| Security scanners | Vulnerabilities |
| Norma | Requirement fidelity |
Every other tool measures your code against an external standard. Norma is the only one that measures it against your spec. That gap is the whole reason it exists.
Introducing the Spec Fidelity Score
A single number for how faithfully an implementation matches its specification. Read it like Lighthouse reads performance. Spec Fidelity is the category, and Norma is the tool that measures it.
Every Spec Fidelity Score should stamp the model and prompt version, so it is reproducible and contestable. The report has an open schema, which is how the number becomes a shared standard rather than one vendor's metric.